This invention relates to a boot or seal retainer for a power transmitting mechanical joint. More particularly, this invention relates to a motor vehicle constant velocity joint outer race boot or seal retainer.
Most vehicles with independent suspension use a halfshaft assembly to transmit power from the engine to the drive wheels. This halfshaft assembly normally has a pair of mechanical joints, one at each end and an interconnecting shaft between the two joints. These mechanical joints are generally constant velocity universal joints.
Most constant velocity universal joints, irrespective of their design, require a continuous supply of grease to operate. These joints use a flexible boot, made from rubber or plastic materials to seal a cavity between the constant velocity universal joint outer race and the interconnecting shaft to which the boot is sealingly engaged. During assembly of the halfshaft, the cavity is filled with a specified type and amount of grease. This supply of grease is expected to lubricate the internal components of the joint for the life of the vehicle. Because this joint is sealed for life, the reliability and integrity of the sealing engagement with both the interconnecting shaft and the joint outer race is critical.
Current boots are designed to interface with grooves on both the interconnecting shaft and the outer race. Once the boot has been located in these grooves, a clamp similar to one shown in U.S. Pat. No. 3,402,436 issued to Oetiker is placed around the boot and outer race and around the boot and shaft. These clamps are then tightened to complete the sealing engagement of the boot.
FIGS. 1 and 2 shows a typical constant velocity universal joint 10 incorporating a prior art sealing arrangement. The boot 12 forms a cavity 14 between the constant velocity universal joint 10 and the interconnecting shaft 16.
The boot 12 has a portion located in a groove 20 machined into the outer surface 22 of the joint outer housing 18. The boot 12 has a second portion located in a second groove 26 in the outer surface 28 of the shaft 16. The boot 12 is sealingly engaged to both the joint outer housing 18 and the shaft 16 by clamps 24 and 30, respectively. A retaining ring 32 is positioned in the interior surface of the housing 18 to retain joint inner race 34, joint cage 36 and balls 38 inside the joint outer housing 18. This design significantly increases the outer profile beyond the outer surface 22 of the joint outer race 18 and requires the addition of the retaining ring 32 to retain the joint internal components 34, 36 and 38.
While the present Omega clamp positioned around the outer race and interconnecting shaft functions satisfactorily, it has several disadvantages. One disadvantage of the Omega clamp is that during the assembly of the joint, the internal components are free to move with respect to the outer race. In the past, a retention mechanism such as the snap ring described above or the like, has been required to retain the internal components inside the outer race. Use of the boot itself for retention has proven to be unreliable for maintaining the components within the joint. Another disadvantage is that the Omega clamp, with its deformable ear, extends from the surface of the joint. In applications where space is at a premium, this extension interferes with the clearance of the rotating joint. While other low profile clamps have been proffered, they require the addition of boot thicknesses and clamp thicknesses to the outside diameter of the outer race. This adds to the overall swing diameter of the joint outer race assembly.
Accordingly, it is desirable to have an assembly which overcomes the present disadvantages. The present invention provides the art with a retention mechanism which retains the internal components within the joint during the assembly of the joint to the halfshaft as well as during assembly of the halfshaft into the vehicle. Also, the present invention provides a low profile boot retention system which requires only the addition of one thickness of the boot retainer to the outside diameter of the constant velocity universal joint outer race.
From the following detailed description, drawings and subjoined claims, other objects and advantages of the present invention will become apparent to those skilled in the art.